`service:check` throwing error

**Intended outcome:**

Should be able to `apollo service:check` my local schema.

**Actual outcome:**

Error thrown when running `apollo service:check` command,

```
yarn apollo service:check
yarn run v1.17.3
$ /path/to/repo/node_modules/.bin/apollo service:check
✔ Loading Apollo Project
⠼ Validating schema against tag current on graph my-api
→ Validating schema
✔ Loading Apollo Project
✖ Validating schema against tag current on graph my-api
→ https://engine.apollographql.com/service/my-api/upgrade.
Comparing schema changes
Reporting result
error Command failed with exit code 2.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

```

**How to reproduce the issue:**

There are two ways.

Option 1:

Configure `apollo.config.js` file pointing to a local schema,

```js
module.exports = {
service: {
localSchemaFile: "./schema.graphql",
},
};

```

Option 2:

Use command with inline args,

```
yarn apollo service:check --localSchemaFile schema.graphql
```

**Versions**

`apollo/2.18.0 linux-x64 node-v11.12.0`

Start with the Apollo CLI service:check command and reproduce the failure using the local schema configured in apollo.config.js or the --localSchemaFile schema.graphql argument. Compare both invocation paths and verify that apollo service:check completes successfully against the local schema without exiting with code 2.

Written by the indexing model from the issue text.